Genetic Variability Studies for Morphological and Yield Traits in Dolichos Bean (Lablab purpureus L.)

Thirty genotypes of Dolichos bean (Lablab purpureus) were evaluated to study the genetic variability on yield, yield contributing and related characters viz. days to 50% flowering, days to first pod set, days to maturity, number of pods per cluster, pod length, width of pod, weight of 10 green pods, number of single podded clusters per plant, number of pods per plant and protein content. The range, genotypic and phenotypic coefficient of variation, heritability, genetic advance and correlation were calculated. The genotypes showed considerable amount of variability for all the traits. The highest and lowest coefficient of variation was observed for single podded clusters per plant and protein content respectively. Little or no difference between the phenotypic and genotypic coefficients of variability in the expression of various horticultural traits studied for viz. protein content, days to 50% flowering, days to first pod set, pod length, pod weight, weight of 10 green pods and days to maturity, indicated that these were less influenced by environment. Phenotypic coefficient of variation was high for the single podded clusters per plant and the lowest phenotypic coefficient of variation was observed in protein content. Days to 50% flowering, pod length, width of pod, weight of 10 green pods accounted for higher heritability and higher genetic advance which suggests the role of additive gene action in the expression of these characters and could be improved through selection. Significant positive phenotypic correlations were observed between yield other yield components viz. days to first pod set, days to 50 per cent flowering, number of pods per plant, weight of 10 green pods and length of pod. In contrast, the correlation between yield and protein content of pods was significantly negative. The genotypes used in the study are of diverse nature and can be used in the breeding programme for development of superior genotypes in Dolichos bean.